The range of y = Sina / (COSA + 2)

The range of y = Sina / (COSA + 2)

The range of y = sin α / (COS α + 2) is y '= [(COS α + 2) cos α + Sin & # 178; α] / (COS α + 2) & # 178; = (COS & # 178; α + 2cos α + Sin & # 178; α) / (COS α + 2) & # 178; = (1 + 2cos α) / (COS α + 2) & # 178; = 0 from 1 + 2cos α = 0, cos α = - 1 / 2, the stationary point α = 2K π ± 2 π / 3; take k =

Y = sina-1 / cosa-2

Y = (sina-1) / (cosa-2) is the slope of the line between point P (COSA, Sina) and point Q (2,1), and point P moves on the circle X & # 178; + Y & # 178; = 1. By using the position relationship between line and circle, the slope range is: [0,4 / 3]. That is, the value range of this function is: [0,4 / 3]